Organic Light Emitting Diode (OLED) display panel comprises a substrate, and an anode, a light-emitting layer and a cathode formed on the substrate. The light-emitting layer is generally produced by a printing method so that liquid light-emitting material covers a pixel region of the OLED display panel. The size of the pixel region of the existing high-resolution display panel is generally 30 μm×180 μm, but the diameter of the droplet formed by the printing method is greater than 30 μm. Moreover, the droplet may deviate from its target region at the time of printing. Therefore, the droplet formed by the printing method may flow to adjacent pixel regions, thereby causing defects such as cross-color, Mura, etc.
The Liquid Crystal Display (LCD) panel comprises an array substrate, an opposed substrate, and a liquid crystal layer sandwiched between the array substrate and the opposed substrate. In order to realize color display, the LCD panel further comprises a color filter layer, which may be disposed on the array substrate or the opposed substrate. The color filter layer may be produced by a printing method so that liquid material of color filter layer covers a pixel region of the LCD panel. At this time, there exists also the problem that the droplet formed by the printing method may flow to adjacent pixel regions, thereby causing defects such as cross-color, Mura, etc.
In order to ensure that the droplet formed by the printing method can cover the pixel region evenly and smoothly, and to prevent the droplet from flowing into adjacent pixel regions, the following method is adopted. A photo resist (PR) resin is used to form the photo define layer(PDL), a fluorination treatment is performed on the surface of the PR resin with CF4 of 60% in CVD environment or the PR resin is irradiated with short-wavelength ultraviolet so that the surface energy of the PR resin is changed. Accordingly, the wetting property of the surface of the pixel define layer can be changed and the droplet can flow into the target pixel region even though it deviates from the target pixel region at the time of printing. However, this method needs to increase investment in apparatus and has a high cost, and this method is unfavorable for mass production.